Thanks, I shall try it out this evening. I wonder if there is a command that acts like a buffer? Waits for the command writing to stdin to complete before passing it all to stdout. With seek on stdout. That would be handy. avconv -i xxx | buf | avconv -i stdin xxx
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RoboJ1MMay 10 '13 at 8:00

1

The error message I appended is specifically related to trying to use pipes with avconv, as pipes are inherently non-seekable. The best one can do is to locate temp.mp4 on a tmpfs or similar in-memory filesystem. /dev/shm/ is a good candidate for this, if one has enough RAM.
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rmsrJun 26 '13 at 0:20

Regarding piping, you can probably do it with named pipes aka fifo. Have a search for mkfifo. Essentially, you use a file as a temporary storage for stout.
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SparhawkApr 8 '14 at 12:10